The beneficial effects of employing auxiliary signaling assemblies have been disclosed in various U.S. patents including U.S. Pat. Nos. 5,014,167; 5,207,492; 5,355,284; 5,361,190; 5,481,409; 5,528,422; 6,005,724; and 6,257,746 all of which are incorporated by reference herein. The mirror assemblies disclosed in some of these patents teach the use of various dichroic mirrors which are operable to reflect a broad band electromagnetic radiation, within the visible light portion of the spectrum, while simultaneously permitting electromagnetic radiation having wavelengths which reside within a predetermined spectral band to pass therethrough. As disclosed in this earlier prior art, these same dichroic mirrors remain an excellent visual image reflector, that is, achieving luminous reflectance which is acceptable for automotive, and other industrial applications, while simultaneously achieving an average transmittance in the predetermined spectral band which is suitable for use as a visual signal at a wide range of distances and for various purposes.
While all of these prior art devices have worked with some degree of success, various shortcomings have been uncovered which have detracted from their wide spread use. Among the several shortcomings which have impeded commercial introduction has been the manufacturing costs associated with applying the rather complex optical coatings which are necessary to form the dichroic mirrors that are employed in these devices.
Still further, other devices have been introduced which diverge, to some degree, from the use of dichroic mirrors. These devices however, when built in accordance with their teachings, have been unable to provide the same performance characteristics as provided by the prior art which employs dichroic mirrors. Still further, other prior art references have described devices which attempt to provide the same functional benefits as described in these earlier patents. These references describe all manner of mirror housing modifications, where for example, lamps are located in various orientations to project light into predetermined areas both internally and/or beside the overland vehicle and to further provide auxiliary signaling or warning capability. Examples of these patents include U.S. Pat. Nos. 4,583,155; 4,646,210; 4,916,430; 5,059,015; 5,303,130; 5,371,659; 5,402,103; 5,497,306; and 5,436,741 to name but a few.
In addition to the shortcomings associated with fabricating a suitable dichroic coating for use in mirror assemblies as described in the prior art, the associated mirror housings have decreased in volume as a result of recent automotive platform design changes. Consequently, the amount of internal space which is available when these same housings are employed is quite limited. Therefore, the size and weight of an enclosed light emitting assembly employed in such signaling devices has become a significant factor in the development and commercial introduction of a suitable product.
To address these and other perceived shortcomings in the prior art, U.S. Pat. No. 6,005,724 disclosed a novel mirror assembly which employed a mirror substrate which is fabricated by using conventional techniques, and which includes a primary mirror surface region which reflects less than about 80% of a given band of visibly discernable electromagnetic radiation; and a secondary region adjacent thereto and through which electromagnetic radiation may pass. In this arrangement, the secondary region reflects at least about 35% of the same given band visibly discernable electromagnetic radiation. In mirrors of this design, the average reflection of the mirror coating is greater than about 50%. This novel invention resulted in dramatic decreases in the manufacturing costs for devices of this type. Still further, the perceived safety advantages of using such auxiliary signaling devices has now been well established, inasmuch as these same signaling assemblies provide a convenient means whereby an operator may signal vehicles which are adjacent to, and rearwardly oriented relative to an overland vehicle equipped with same, of their intention, for example, to change lanes, turn, or perform other vehicle maneuvers which would be of interest to vehicles traveling adjacent to thereto.
A signaling assembly which achieves these and other advantages is the subject matter of the present application.